大功率400Hz逆变电源数字控制设计

Digital Control Design of High Power 400Hz Inverters

为了实现大容量中频逆变器的数字控制,在两级H桥结构基础上,分析了数字控制时由采样、计算及脉宽调制过程产生的延时及其对系统性能的影响。采用P+谐振控制,通过在连续域设计中引入等效延时环节的方法,对数字控制参数进行了设计。建立了一个100kVA的400Hz/115V逆变器仿真模型,通过离散数字仿真对所提出的方法进行了验证。采用DSP和现场可编程序门阵列(FPGA),以同一个正弦信号为参考,生成了单更新采样和双更新采样时的PWM波形,得到各波形基波分量与参考信号的相位差,与理论分析相一致,证明了延时分析的正确性。

In order to implement digital control in high power medium frequency 400Hz/115V inverters,the delay induced by the processes of sampling,computing and PWM during digital control and its impact on the system performances are analyzed based on two-H-Bridge cascaded topology.The control parameters are designed in the continuous domain design by introduced the equivalent time delay when P＋resonant controller are adopted.The discrete simulation on a single-phase 100kVA medium frequency inverter model was presented,and the simulation shows the effectiveness of the proposed scheme.PWM waveforms in the single and double update mode operation are generated simultaneously with a common reference sinusoidal signal and the differences between each fundamental phase and reference signal phase are obtained by DSP and field programmable gate array（FPGA）.The results coincide with theoretical analysis.